The present invention has for its object a method and an equipment for carrying out the degradation of organic products, by-products and scraps of human, animal or vegetable origin. More specifically, the subject matter of the invention is a process and an improved plant for performing a continuous methanizing of solid and/or liquid organic compounds.
In the European patent application EP-A-0074290 of the applicants, there has been described a method for carrying out a degradation in an anaerobic medium, for instance of methanogenesis of organic products, by-products or scraps of human, animal and/or vegetable origin, consisting in feeding the products to be degraded into a closed vessel after having possibly sowed the products with a suitable substrate, imposing upon the said products a direction of circulation within the vessel, recovering the gas produced called biogas evolved above the body of products and discharging the degraded products. This process describes various means for obtaining a pneumatic thrust of the substrate and a homogenization of the latter to accomplish a directed forced circulation and a good fluidizing thereof.
These means comprise feeding or discharging the products pneumatically preferably, through siphons by a pneumatic thrust; inducing sudden variations in pressure of the gas contained within the closed vessel in combination with a reintroduction of the biogas into the body of products present in the vessel.
In the method forming the subject matter of the European patent application EP-A-0074290, there has also been described a blowing of biogas by means of biref and successive jets through ducts opening into the bottom of the fermentation tank. Thus was carried out a simultaneous injection of gas into the whole bottom of the fermentation tank through the intermittent emission of brief jets. It appeared now during additional searches that this simultaneous blowing into the whole fermentation vat by means for time-bound short and successive jets did not lead to the desired result so that the fluidizing often was not perfect. It could moreover be found during these searches that the density of the substrate would vary from the feed shaft to the discharge shaft in such a manner that a uniform injection of biogas throughout the fermentation vat is inadequate because it does not at all take into account this difference in density.